Move goal decreasing

My move goal is set to 400 calories. I recently hit 425 calories (closed the move ring). It was updated on my watch and iPhone. I looked at my watch again, about an hour later, and my move calories were only at 300 and my ring was no longer closed. Is there a reason for this? The only thing I can think of is that I had started a 10 min yoga workout using the workout app but forgot to “end” the workout for 30 mins? I turned my watch and iPhone off and on to see if the calories would correct themselves but they did not.